Western Digital Corporation
MX ˙ BMV ˙ US9581021055
SecurityMX:WDC / Western Digital Corporation
InstitutionJanus Henderson Group Plc
Latest Disclosed Ownership51,727 shares
Latest Disclosed Value $ 13,996,380
Janus Henderson Group Plc reports 47.60% increase in ownership of WDC / Western Digital Corporation

On May 18, 2026 - Janus Henderson Group Plc filed a 13F-HR/A form disclosing ownership of 51,727 shares of Western Digital Corporation (MX:WDC) valued at $13,996,380 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 17, 2026 disclosing 35,045 shares of Western Digital Corporation. This represents a change in shares of 47.60% during the quarter.

Institutional Ownership: 13F and NPORT Filings

The Security and Class in the table below are shown exactly as filed by the investor. We do our best to track continuity of investments through acquisitions, and this will be reflected in the table as changes in names. In addition to descriptive data, performance of the investment is shown over time. To calculate quarterly performance, we first calculate cost basis of the shares purchased during the quarter, then use that to calculate gross profit. Quarterly return is Gross Profit / Starting Portfolio value.

Note that cost basis is calculated and stored in thousands, so small quarterly changes in shares frequently result in a cost basis of zero.

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Disclosed Equity Positions (from 13F/NPORT Filings)
File
Date		 Effective
Date		Form Security Class ID Avg Price
Paid (Est)		 Reported
Shares		 ΔShares ΔShares
(%)		 Reported
Value
(x1000)		 ΔValue
(%)		 Alloc
(%)		 ΔAlloc ΔAlloc (%) Cost Basis
(x1000)		 Unrealized
Gain/Loss
(x1000)
2026-05-18 2026-03-31 13F/A-1 WESTERN DIGITAL COM 958102105 51,727 16,682 47.60 13,996 131.88 0.0067
2026-05-15 2026-03-31 13F WESTERN DIGITAL COM 958102105 51,727 16,682 13,996 0.0026
2026-02-17 2025-12-31 13F WESTERN DIGITAL COM 958102105 35,045 -4,424 -11.21 6,036 27.40 0.0027
2025-11-14 2025-09-30 13F WESTERN DIGITAL COM 958102105 39,469 -300 -0.75 4,738 86.32 0.0022
2025-08-14 2025-06-30 13F WESTERN DIGITAL COM 958102105 39,769 -6,005 -13.12 2,544 36.79 0.0012
2025-05-15 2025-03-31 13F WESTERN DIGITAL COM 958102105 45,774 -25,800 -36.05 1,859 -56.44 0.0010
2025-02-14 2024-12-31 13F WESTERN DIGITAL COM 958102105 71,574 -1,163,758 -94.21 4,269 -94.95 0.0022
2024-11-14 2024-09-30 13F WESTERN DIGITAL COM 958102105 1,235,332 -225,907 -15.46 84,435 -23.73 0.0432
2024-08-14 2024-06-30 13F WESTERN DIGITAL COM 958102105 1,461,239 1,418,881 3,349.74 110,711 3,732.12 0.0593
2024-05-15 2024-03-31 13F WESTERN DIGITAL COM 958102105 42,358 5 0.01 2,890 30.25 0.0016
2024-02-14 2023-12-31 13F WESTERN DIGITAL COM 958102105 42,353 -229 -0.54 2,218 14.15 0.0013
2023-11-14 2023-09-30 13F WESTERN DIGITAL COM 958102105 42,582 -4,688 -9.92 1,943 8.43 0.0013
2023-08-14 2023-06-30 13F WESTERN DIGITAL COM 958102105 47,270 -3,137 -6.22 1,793 -5.58 0.0011
2023-05-15 2023-03-31 13F WESTERN DIGITAL COM 958102105 50,407 9,404 22.93 1,898 46.79 0.0013
2023-02-14 2022-12-31 13F WESTERN DIGITAL COM 958102105 41,003 -3 -0.01 1,293 -3.07 0.0009
2023-01-13 2022-09-30 13F/A-1 WESTERN DIGITAL COM 958102105 41,006 112 0.27 1,334 -27.22 0.0010
2022-11-14 2022-09-30 13F WESTERN DIGITAL COM 958102105 41,006 112 1,334 0.0010
2022-08-15 2022-06-30 13F WESTERN DIGITAL COM 958102105 40,894 -527,532 -92.81 1,833 -93.51 0.0013
2022-05-16 2022-03-31 13F WESTERN DIGITAL COM 958102105 568,426 -516,217 -47.59 28,222 -60.10 0.0136
2022-02-14 2021-12-31 13F WESTERN DIGITAL COM 958102105 1,084,643 547,213 101.82 70,730 133.18 0.0295
2021-11-16 2021-09-30 13F WESTERN DIGITAL COM 958102105 537,430 -4,844 -0.89 30,333 -21.40 0.0133
2021-08-16 2021-06-30 13F WESTERN DIGITAL COM 958102105 542,274 127,831 30.84 38,594 39.51 0.0165
2021-05-17 2021-03-31 13F WESTERN DIGITAL COM 958102105 414,443 -261,414 -38.68 27,663 -26.10 0.0126
2021-02-16 2020-12-31 13F WESTERN DIGITAL COM 958102105 675,857 476,256 238.60 37,435 413.09 0.0174
2020-11-16 2020-09-30 13F WESTERN DIGITAL COM 958102105 199,601 60,971 43.98 7,296 19.24 0.0038
2020-08-14 2020-06-30 13F WESTERN DIGITAL COM 958102105 138,630 -1,797,963 -92.84 6,119 -92.41 0.0034
2020-05-14 2020-03-31 13F WESTERN DIGITAL COM 958102105 1,936,593 23,237 1.21 80,596 -33.62 0.0555
2020-02-18 2019-12-31 13F WESTERN DIGITAL COM 958102105 1,913,356 553,288 40.68 121,419 49.73 0.0622
2019-11-14 2019-09-30 13F WESTERN DIGITAL COM 958102105 1,360,068 1,119,448 465.23 81,091 608.78 0.0439
2019-07-31 2019-06-30 13F WESTERN DIGITAL COM 958102105 240,620 123,473 105.40 11,441 103.21 0.0062
2019-04-30 2019-03-31 13F WESTERN DIGITAL COM 958102105 117,147 37,388 46.88 5,630 90.85 0.0031
2019-02-06 2018-12-31 13F WESTERN DIGITAL COM 958102105 79,759 -23,067 -22.43 2,950 -51.00 0.0019
2018-11-09 2018-09-30 13F WESTERN DIGITAL COM 958102105 102,826 -1,001,308 -90.69 6,020 -92.96 0.0032
2018-08-10 2018-06-30 13F WESTERN DIGITAL COM 958102105 1,104,134 -412,493 -27.20 85,471 -38.92 0.0487
2018-05-14 2018-03-31 13F WESTERN DIGITAL COM 958102105 1,516,627 -1,034,792 -40.56 139,929 -31.04 0.0825
2018-03-12 2017-12-31 13F/A-1 WESTERN DIGITAL COM 958102105 2,551,419 -19,186 -0.75 202,918 -8.63 0.1250
2018-02-09 2017-12-31 13F WESTERN DIGITAL COM 958102105 2,551,419 -19,186 202,918
2017-11-14 2017-09-30 13F WESTERN DIGITAL COM 958102105 2,570,605 575,772 28.86 222,092 25.66 0.1423
2017-08-17 2017-06-30 13F/A-1 WESTERN DIGITAL COM 958102105 1,994,833 1,164,954 140.38 176,746 158.03 0.1205
2017-08-14 2017-06-30 13F WESTERN DIGITAL COM 958102105 1,994,833 1,164,954 176,746
2017-05-03 2017-03-31 13F WESTERN DIGITAL COM 958102105 829,879 -2,506 -0.30 68,498 21.10 0.4809
2017-01-30 2016-12-31 13F WESTERN DIGITAL COM 958102105 832,385 778,264 1,438.01 56,565 1,687.77 0.4172
2016-10-24 2016-09-30 13F WESTERN DIGITAL COM 958102105 54,121 14,511 36.63 3,164 69.02 0.0233
2016-07-29 2016-06-30 13F WESTERN DIGITAL COM 958102105 39,610 -37,864 -48.87 1,872 -48.84 0.0156
2016-05-12 2016-03-31 13F WESTERN DIGITAL COM 958102105 77,474 -816,149 -91.33 3,659 -93.18 0.0297
2016-02-03 2015-12-31 13F WESTERN DIGITAL COM 958102105 893,623 -8,695 -0.96 53,667 -25.12 0.4306
2015-11-16 2015-09-30 13F WESTERN DIGITAL COM 958102105 902,318 -11,700 -1.28 71,671 -0.02 0.6313
2015-08-17 2015-06-30 13F WESTERN DIGITAL COM 958102105 914,018 5,464 0.60 71,682 -13.30 0.5633
2015-06-02 2015-03-31 13F/A-1 WESTERN DIGITAL COM 958102105 908,554 -176,195 -16.24 82,674 -31.17 0.6378
2015-05-15 2015-03-31 13F WESTERN DIGITAL COM 958102105 908,554 82,674
2015-02-12 2014-12-31 13F WESTERN DIGITAL COM 958102105 1,084,749 345,300 46.70 120,120 66.93 0.8661
2014-11-12 2014-09-30 13F WESTERN DIGITAL COM 958102105 739,449 -9,289 -1.24 71,959 4.12 0.6769
2014-08-13 2014-06-30 13F WESTERN DIGITAL COM 958102105 748,738 -130,540 -14.85 69,112 -14.40 0.6454
2014-05-08 2014-03-31 13F WESTERN DIGITAL COM 958102105 879,278 202,408 29.90 80,740 42.17 0.7860
2014-01-14 2013-12-31 13F WESTERN DIGITAL COM 958102105 676,870 71,833 11.87 56,793 48.08 0.5738
2013-11-12 2013-09-30 13F WESTERN DIGITAL COM 958102105 605,037 -1,347 -0.22 38,353 0.28 0.4231
2013-08-15 2013-06-30 13F WESTERN DIGITAL COM 958102105 606,384 606,384 38,245 0.4471
Legend
Shares
The total number of shares held by the institution at the end of the reporting period (the effective date). This is provided in the filing.
Value
The total value of the shares as of the effective date. This is provided in the filing.
Avg. Share Price
The weighted average share price of the shares held by the institution. We use FIFO accounting to determine this price
Class
This is the security class as indicated by the filer. There are a variety of values for this field. Common values include "EC" = equity common, "EP" - equity preferred
Allocation (%)
The percent of the institution's portfolio that this position represents. This is provided in NPORT filings. For 13F filings, we calculate it.
Change in Allocation
The change in allocation from the prior reporting period. This is calculated as current allocation - prior allocation.
Change in Allocation (%)
The percent change in allocation from the prior reporting period. This is calculated as (current allocation - prior allocation) / prior allocation.
Cost Basis
The total cost of the shares held. This is calculated as reported shares * avg. share price
Unrealized Gain/Loss
This is the market value of the position as of the effective date minus the cost basis.